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Tuneable electronic coupling in linked bis(cubane) cobalt-oxo clusters
Vincent J P Maddi1,2, T Don Tilley1,2
1Department of Chemistry, University of California Berkeley California 94720 USA tdtilley@berkeley.edu.
Chemical Science
|April 6, 2026
Summary
New cobalt-oxo bis(cubane) complexes were synthesized using bridging ligands. Pyrazine-bridged complexes show tunable electronic coupling between cobalt-oxo cubane units, impacting water oxidation catalysis.
Area of Science:
- Inorganic Chemistry
- Catalysis
- Electrochemistry
Background:
- Cobalt-oxo cubanes are known catalysts for water oxidation.
- Bridging ligands are crucial for creating multi-nuclear complexes with potential catalytic applications.
Purpose of the Study:
- To synthesize and characterize a family of cobalt-oxo bis(cubane) complexes.
- To investigate the electronic coupling between cobalt-oxo cubane subunits.
- To evaluate the influence of bridging ligands on catalytic properties and electrochemical behavior.
Main Methods:
- Synthesis of cobalt-oxo bis(cubane) complexes utilizing 4,4'-bipyridine and pyrazine as bridging ligands.
- Electrochemical analysis, specifically half-wave potential measurements, to assess electronic communication.
- Ligand substitution to tune the electronic properties of the complexes.
Main Results:
- Successful synthesis of cobalt-oxo bis(cubane) complexes with both 4,4'-bipyridine and pyrazine linkers.
- Pyrazine-bridged complexes demonstrated significant inter-cubane electronic coupling.
- Electronic coupling was found to be tunable via ligand substitution.
- Electrostatic contributions and ion-pairing effects influenced the observed electrochemical potentials.
Conclusions:
- Cobalt-oxo bis(cubane) complexes can be effectively constructed using various bridging ligands.
- The pyrazine linker facilitates electronic communication between catalytic cobalt-oxo cubane units.
- Electrolyte ion-pairing significantly impacts the electrochemical behavior, leading to non-conformist observations.
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